Today I finished, alodined, primed and riveted the new ends for the lap belt attach points. There is plenty of room for the seat now, but the belts are a little short to adjust easily with my butt in the Velo seat.
Seat position is critical and the lap belt length will be OK for now, but I would prefer to order a slightly longer Hooker lap belt later on than adjust the seat position again to suit the belt.